FORT WASHINGTON — Arbor Hill, a 70-acre estate here designed by an internationally renowned architect and interiors completed by an equally well-regarded team from New York, has come up for sale for $30 million and offers a rare glimpse inside the compound of a multimillionaire local executive.

Arbor Hill was designed by Rafael Vinoly, the architect who locally designed the Kimmel Center for the Performing Arts, for Dennis Alter, former president and CEO of Advanta Corp. The 40,000-square-foot stone house off Sheaff Lane appears as a contemporary interpretation of a fortress built around a main courtyard that has a tower separating wings. The living room, of a heroic scale, doubles as a full-scale basketball court.

The interior of the house was planned by Sils Huniford Associates Inc., a prestigious interior design team known for their high-end clients and upscale tastes. The decor, with antiques and other accouterments, complemented Alter’s art collection, which includes abstract expressionist works.

Arbor Hill includes 20,000 additional square feet in a “playhouse” that has an indoor tennis court, weight room and a two-bedroom caretaker’s apartment. Two stone farmhouses also are part of the property.

The house was initiated by Alter at a different time for him and Advanta. He started to acquire and assemble properties in the 1990s that would eventually be combined into the ground for the estate Alter named Arbor Hill for its pastoral and forested, hilly landscape. The property is protected on all of its sides by a horse farm, state park and the Highlands mansion and gardens. At the time, Advanta, the credit-card company Alter’s father founded in 1951, was experiencing revenue growth and a steadily rising share price.

Vinoly, who has completed notable projects around the world, was Alter’s pick to design his new residence.

“I knew Rafael on a personal basis,” Alter said in an interview. “We ski together and vacation together.”

In 2000, Alter, his wife and four children moved into their new house, which some estimates peg at costing between $50 million and $80 million to fully build out and decorate.

Eleven years later, Alter’s life has changed.

Advanta of Spring House was liquidated in proceedings approved by a bankruptcy court earlier this year. It has also changed personally, which is the main reason Alter put the estate up for sale.

“I’m divorced now and had four kids living at home and now I have two,” he said. “They will eventually be out of high school so it’s more house than I need for me and my kids.”

Seldom does a property on this scale and price range come on the market in the Philadelphia area.

Reggie Hunt, a real estate agent with Long & Foster is affiliated with Christie’s International Real Estate, is marketing the property on an international basis. Though a local buyer has shown interest, Hunt said, it wouldn’t surprise her if someone wealthy from outside the United States stepped up to buy Arbor Hill.

“The question is finding someone who is willing to pay that kind of money,” she said, noting that money from outside the country has started to look at residential real estate that may seem undervalued because of the sluggish housing market.

Others are skeptical a house in that price range will be an easy sell.

“There is no $30 million market in this area,” said Robin Gordon, an agent with Prudential Fox & Roach who focuses on high-end Main Line residences. “We’re having trouble selling houses for $3 million in this market.”

It will be a challenge to sell the property as a single asset but it may have more success being subdivided and then sold, Gordon said.

“The parts are usually worth more than the whole,” she said.

That’s an option Alter said he hasn’t considered at this point. For now, he has confidence a buyer is out there who wants a Vinoly-designed house on 70 protected acres near Philadelphia.